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US Army Corps of Engineers
Mississippi Valley Division Website

Who We Are

The National Ecosystem Restoration Planning Center of Expertise (ECO-PCX) is based in the Mississippi Valley Division with a virtual team from across the nation that provides ecosystem restoration planning services to civil works study teams throughout the U.S. Army Corps of Engineers.

The ECO-PCX leverages a 13-member virtual team with a large network of ad hoc technical experts that can provide specialized assistance with ecosystem restoration planning. The ECO-PCX team is comprised of the Director, Operating Director, Account Managers, PCX Independent External Peer Review Lead, and a Model Review Manager.

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The ECO-PCX works in all eight Major Subordinate Commands and in Corps of Engineers Districts across the nation. In some cases, these services are provided with the ECO-PCX as the lead responsible for managing reviews.  In other cases, the ECO-PCX is supporting another planning center that serves as the business line lead but needs support for an environmental or ecosystem aspect of a study review. 

Engaging the ECO-PCX early offers teams the ability to access expert support in the critical initial scoping stages of a study and to maintain coordination throughout the planning process. Ideally the ECO-PCX should be consulted when a district begins to negotiate a feasibility study with a non-Federal sponsor. This helps frame the nature of an investigation and identify study support tools such planning models, best practices, recent lessons learned, and available technical experts.

Technical experts from the ECO-PCX support teams in planning charettes or other workshops that gather information and shape potential solutions to water resources problems. Interaction between the ECO-PCX and a study team carries-on throughout the study with the center’s critical involvement in developing a Review Plan, selecting and approving/certifying a planning model, performing various levels of independent review, and participating in vertical team engagements at milestone meetings and other coordination events.

1. Technical Services. Provide technical services to District PDTs from subject matter experts and/or at the direction of a Regional Management Board or the HQ Planning Advisory Board (PAB); accomplish costly, highly complex, and controversial studies or key analytical components of such studies for District PDTs, and multiregional or national efforts, on a reimbursable basis. Provide advice to HQUSACE, the laboratories, and other partners or stakeholders on significant regional or nationwide planning issues.
2. Peer Review. Provide for and manage Agency Technical Review (ATR) and maintain rosters of regional technical specialists for conducting timely ATR. Function as the Review Management Organization for Independent External Peer Review (IEPR) to interface with the performing organization external to the Corps of Engineers conducting the IEPR and the District PDT.
3. R&D. Assist in identifying Research and Development (R&D) priorities within the mission area to ensure field driven needs are identified and prioritized and coordinate the recommendations with the PAB and the deputy, Planning Community of Practice.
4. Training. Conduct training opportunities related to the assigned mission area to promote and maintain planning technical competency. Support the Planning Associates (PA) program through development and training of PAs along the CW business lines and specific PCX functions. Support national goals in enhancing professional and technical development, sharing knowledge, and promoting communication within the Community of Practice (CoP) and through coordination and integration of planning policies with the HQUSACE Planning CoP.
5. Model Certification. Certify or approve for use the planning models identified in the Project Review Plans and add to the planners' toolbox of certified models using the approved model certification protocol.
6. Policy Development Support. Centers would supplement the HQUSACE staff in policy compliance review, if requested, on a reimbursable basis, on projects where the center has had no prior participation. Centers would also provide assistance with exporting policy training to the field or providing review of draft policy.
7. Process Improvement. Develop standard processes and procedures related to their mission areas to support District execution. Support Corps-wide process improvement initiatives through their subject matter experts' participation on process improvement teams.
8. Lessons Learned. Manage a program of sharing lessons learned through coordination with the MSC regional planning expertise centers, sponsoring workshops, technology transfer, or use of intranet resources such as SharePoint.

The ECO-PCX may serve as the RMO for feasibility studies or other work performed to prepare a civil works decision document. The RMO coordinates the Agency Technical Review and the Independent External Peer Review of decision documents and other planning products. The RMO role includes forming review teams and certifying the completion of reviews. In addition, the ECOPCX will engage other centers, such as cost engineering or risk management, as needed to support other independent reviews required by law or Corps policies.

The RMO may be a Planning Center of Expertise, the Risk Management Center or a Major Subordinate Command. Identification of an RMO should follow the guidance in EC 1165-2-217 Civil Works Review Policy. In most cases the RMO will be the center of expertise for the primary business line of the study subject matter. For example, the Flood Risk Management PCX is the RMO for most flood risk studies, and the ECO-PCX is the RMO for most ecosystem restoration studies. Multipurpose studies may be an exception along with certain programs that have decision making authority delegated to the MSC. The Review Plan, discussed in detail below, will clearly identify the RMO for a study.

In some cases, the ECO-PCX will support other planning centers that serve as the Review Management Organization for other business lines (flood risk, navigation, coastal or water management). In these instances, the ECO-PCX function is to provide services, such as model review or planning support, as a secondary service and not serve as the Review Management Organization. Examples of this are common for Flood Risk Management studies that may involve environmental impacts and mitigation planning as part of the feasibility analysis. In those instances, the  FRM-PCX is the Review Management Organization, and the ECO-PCX is called upon to support model selection, model review and mitigation planning. Similar arrangements are common with some of the other planning centers focused on coastal storms and navigation (both deep draft and inland) mission areas.

A Review Plan defines the scope, level of risk, and level of peer review for the planning, design and construction of a Civil Works project. The ECO-PCX engages with Districts during the development of a feasibility study Review Plan. The ECO-PCX Account Manager assists the District team in preparing the Review Plan. This coordination helps identify  the levels of independent review needed and solidifies the ECO-PCX role as the Review Management Organization.

The Review Plan serves as a formal guide to the types of reviews to be conducted, outlines the review schedules and costs, and identifies the expertise required on the review teams. The ECO-PCX recommends approval of Review Plans to the MSC Commander and if appropriate may endorse a risk-informed assessment to exclude a study from Independent External Peer Review. The Review Plan should identify all of the planning models to be used and clearly indicate the status of the models.

Once the ECO-PCX and PDT agree upon the content and details of the Review Plan, the ECO-PCX Operating Director will endorse the Review Plan and recommend its approval at the MSC.

An Agency Technical review (ATR) is performed to "ensure the quality and credibility of the government's scientific information" as required by Corps policy and other Federal laws and regulations.  Most planning products that make up parts of a decision document package and supporting files will undergo ATR. This includes products of engineering work, environmental compliance, economic analysis, plan formulation, real estate, and work-in-kind from a sponsor or sponsor’s contractor. 

When the ECO-PCX serves as the RMO, the center is responsible for assembling the ATR team and managing the overall execution of the ATR in accordance with an approved Review Plan. 

Some key factors governing the conduct of ATR include:

• ATR should be conducted following the details outlined in an approved Review Plan.

• The ECO-PCX Account Manager recruits and recommends an ATR Lead for approval by the ECO-PCX Operating Director.

• The ATR Lead should be from outside of the home MSC.

• The ATR Lead assembles the ATR Team members. All reviewers must be ATR certified.

• Typically, an ATR is performed on both the draft report and the final report.

• ATR is conducted concurrently with other reviews (public review, Type I IEPR, and legal and policy reviews).

• DrChecks is used to document ATR comments and comment resolution.

• EC 1165-2-217 outlines a comment dispute resolution process. The process is stepwise from reviewer to PDT, ATR Lead to PDT Lead, ECO-PCX Operating Director to Planning Chief, and then Vertical Team issue resolution. Disputed comments can be closed in DrChecks with notations for higher level engagement.

• The ATR Lead prepares ATR Reports at the conclusion of each ATR. The ATR Report is an important component of study documentation package.

• The ATR Lead may participate in key meetings such as In-Progress Reviews or Milestones. The ECO-PCX has developed a set of standard operating procedures for conducting Agency Technical Reviews.

An Independent External Peer Review (IEPR ) is the most independent level of review performed on civil works products in cases that meet criteria where the risk and magnitude of the proposed project are such that a critical examination by a qualified team outside of USACE is warranted. Federal laws (WRDA 2007 & WRRDA 2014) prescribe the circumstances for conducting IEPR. Corps policy also adds circumstances where IEPR should be performed. Two types of IEPR may be performed Type I (planning phase) and Type II (Safety Assurance Review – may occur in planning, design and construction phases). When the ECO-PCX serves as the RMO, the center will be responsible for coordinating the IEPR and managing the overall execution of it following the details contained in an approved Review Plan.

Some key factors governing the conduct of IEPR include:

• IEPR should be conducted following an approved Review Plan and the Type I IEPR Standard Operating Procedures.

• The ECO-PCX Account Manager works with teams to perform a risk assessment on the factors impacting whether or not to perform a Type I IEPR. This assessment is captured in the Review Plan.

• The ECO-PCX Operating Director may endorse the risk assessment and recommend proceeding with an IEPR exclusion request.

• The ECO-PCX IEPR Lead coordinates the planning and acquisition phases that lead up to starting the IEPR. This work requires attention to detail, extensive coordination with the PDT and contracting services, and may take as much as 180 days to complete.

• An Outside Eligible Organization (OEO) is contracted to select the review panel members and oversee the IEPR.

• Federal law requires USACE to report back to Congress on IEPR decisions and outcomes. These mandatory reporting requirements require coordination between the PDT, MSC, RIT and others.

• Typically IEPR is performed on the draft report only.

• IEPR is conducted concurrently with other reviews (public, ATR, and legal/policy reviews).

• The OEO prepares an IEPR Report after the review. The report is an important component of study documentation package.

• The IEPR Panel may be invited to participate in the Agency Decision Milestone.

• The PDT will prepare a response to comments that will accompany the final report.

Providing technical training is an important ECO-PCX service. The center offers a range of technical and planning support training opportunities. These can cover practical guidance on how to accomplish aspects of planning to more-advanced and specialized technical training. A few examples of this service are discussed below.

The center offers an ecosystem restoration course to the USACE Planning Associates Program. The ECO-PCX owns the module and produces the training. The course has been offered at the New Orleans District and the Rock Island District to vary the restoration experts and example projects featured in the course. An estimated 100+ Planning Associates graduates have completed the ecosystem restoration course taught by the ECO-PCX instructor team.

Other training can be tailored to specific regions to support model development and to assist teams in conducting studies. Over the last few years the ECO-PCX has successfully partnered with ERDC researchers and modeling experts to offer instruction in planning model applications and model development. The workshop format instruction results in leveraged training outcomes that broadcast skills to a large group and also lead to the development modeling applications for specific regions or investigations. Strong examples of the success include a new model for the southern California coastal area, a new freshwater mussel model for the Mississippi River, and expanded model applications for existing tools in the state of Texas.

The center engages technical experts from Corps labs to aid in training and in the development of applied research to support planning studies. This work is normally conducted as part of the Environmental Research Area Review Group (ERARG) annual statement of need evaluations. The ECO-PCX assist District staff in identifying research needs and developing statements that illustrate the need and potential benefits of new research. Through this work ECO-PCX team members have helped develop new tools that support planning teams and we have engaged experts from ERDC to support planning teams around the country.

In 2003, the U.S. Army Corps of Engineers established the National Ecosystem Planning Center of Expertise (ECO-PCX) to support ecosystem restoration project planning. The ECO-PCX performs independent project reviews, technical training, expert planning support, and model development and review for teams across the 38 U.S. Army Corps of Engineers districts.

The timeline below highlights key actions related to the history of the ECO-PCX.

  • 2002 - The National Academy of Sciences releases “Review Procedures for Water Resources Planning”. This report called for the establishment of independent review at multiple levels and utilizing talent from national centers of expertise.
  • 2003 - U.S. Army Corps of Engineers Headquarters established Planning Centers of Expertise for major mission areas (flood risk management, hurricane and coastal storm damage, deep draft navigation, inland navigation, and ecosystem restoration).
  • 2006 - The U.S. Army Corps of Engineers Director of Civil Works issues a memo re-emphasizing the importance of the Planning Centers of Expertise. The memo calls for utilizing the centers in the conduct of independent reviews.
  • 2007 - Congress passes the Water Resources Development Act of 2007 that codifies the establishment of the U.S. Army Corps of Engineers Planning Centers of Expertise.
  • 2008 - The U.S. Army Corps of Engineers Director of Civil Works issues a memo listing the roles and responsibilities of the planning centers. The eight areas identified in the memo form the core set of duties carried out today by the ECO-PCX.
  • 2013 - The U.S. Army Corps of Engineers Chief of Engineers delegates to the Director of Civil Works the authority to exclude from peer review a study for a project with an estimated total cost, including mitigation costs, of more than $45 million that meet the established criteria.
  • 2017 - The U.S. Army Corps of Engineers Director of Civil Works issues a memo delegating the certification of models for single/limited use and the approval of certification plans to the Director of the PCX.
  • 2018 - The U.S. Army Corps of Engineers issues a review policy for the implementation of Independent External Peer Review and addresses Office of Management and Budget peer review requirements for Civil Works projects.
  • 2018 - The U.S. Army Corps of Engineers Director of Civil Works issues a memo delegating the certification of models to the Directors of the Planning Centers of Expertise and the assignment of subject matter experts for the model review team to the Office of Water Project Review.


Planning models used by the U.S. Army Corps of Engineers. to support decision making must be certified to assure quality.

Model Categories

There are several categories used to describe planning models:

Certified - The planning model was developed by the U. S. Army Corps of Engineers and has been reviewed and approved for regional or nationwide application in accordance with documented geographic range, nation-wide application in accordance with documented best practices and its designed limitations. 

In Review – The planning model is under review and not available for current use.

Approved for use - The planning model is presently approved for regional or nationwide use in accordance with documented geographic range, best practices, and its designed limitations. 

Approved for single use - The planning model has been approved for use on one or more U. S. ARMY CORPS OF ENGINEERS projects.  It has not been approved for regional or nation-wide application. 

Not approved – The planning model has not been reviewed and/or certified for use in Planning decisions

The Model Certification process:

The following is a step by step description of the process used to certify ecosystem restoration models by the U.S. Army Corps of Engineers.

1. The model developer or end user (Proponent) initiates consultation with the ECO-PCX.  

2. The Proponent works with PCX to identify potentially applicable models. 

3. ECO-PCX identifies review coordinator.  The review coordinator will work with the proponent to establish a framework for coordinating the receipt of model documentation, development of the model certification/approval plan, and determining the appropriate level of funding for these activities.

4. Model Review Plan Development.  The model review plan is developed specifically to manage the independent model review and approved by the Director of the ECO-PCX.

5. Subject Matter Expert. A subject matter expert is assigned by the Office of Water Project Review to be part of the model review team.  

6. Kickoff Meeting.  A meeting that includes representatives of the ECO-PCX, the Proponent, and the model review team to assure all reviewers understand the scope and the approach for review of the models. 

7. Review of Model.  An assessment of the model using the documentation provided by the Proponent and the ECO-PCX.  

8. Results Meeting. The model review team meet with the ECO-PCX and Proponent to discuss review comments and recommendations. 

9. Proponent and ECO-PCX Summary.  Based on the review comments, the ECO-PCX will identify actions or modifications the proponent needs to undertake in order to gain a recommendation for approval.  The ECO-PCX will close-out the review when it determines identified issues have been resolved to its satisfaction.

10. ECO-PCX Recommendation Package.  The ECO-PCX Model Review Manager compiles a model approval or certification recommendation package for the ECO-PCX Operating Director.  

11. ECO-PCX Operating Director Review. The Operating Director of the ECO-PCX reviews the model recommendation package and recommends model approval or model certification under one of the delegated authorities to the ECO-PCX Director. 

12. ECO-PCX Director Approval. The ECO-PCX Director reviews the model recommendation package.  If the Director agrees with the recommendation, a memo should be signed documenting the approval/certification.  

13. Approval Memo Distribution. The ECO-PCX Operating Director distributes the model approval/certification memo by email to the model review team, the model review manager, the home MSC and the Project Delivery Team.

14. Model Library Update. A copy of the model and all relevant documentation will be uploaded onto the Ecosystem Restoration Model Library. 

Is there a formal process for initiating consultation on a model with the Ecosystem Restoration Planning Center of Expertise (ECO-PCX)?

Unless a District maintains specific requirements related to model review and certification/approval (e.g., directing requests through a supervisor), planners can reach out directly to Nate Richards or Greg Miller through phone or e-mail to discuss the process for model certification and next steps.

Is every ecological planning model required be certified prior to the tentatively selected plan (TSP) milestone, assuming it has not already been previously certified?

A planning model should always be certified or approved before a project delivery team (PDTs) starts using it to produce data for use in a study, per the USACE planning model policy. While PDTs working on ecosystem restoration studies generally need to start using their models before the TSP milestone, the certification/approval timeline will differ across studies based on numerous factors. However, there may be cases where model certification/approval happens post-TSP – for example, in cases where mitigation planning is required, model use may not come until later in the study process.

How are certified models adjusted when new scientific findings contradict or otherwise change the variables currently used in a certain model?

The ECO-PCX has a formal reevaluation process in place for model re-approval and recertification, which must take place at a minimum of every seven years. In cases where new scientific evidence requires reassessment of a model before the seven year period expires, the ECO-PCX uses the same reevaluation process to consider the original certification rationale, review the new information and determine how it changes the components of the existing model, and re-certify the model, as appropriate.

Is there a requirement to use scientific literature-based sources in model development and documentation, or can model certification rely solely on expert professional judgement?

The basis of evidence for certifying models ranges widely. Models for rare species or habitat types may be primarily based on expert professional judgement and experience in the field given the sparsity or complete lack of literature or data, and therefore are documented to the best of the PCX’s ability. While the citation of at least some peer reviewed literature is preferred for all model certification, it is sometimes impossible. When this is the case, the ECO-PCX documents uncertainties and potential complications related to the lack of data to ensure that these issues are clearly outlined.

Are there model certification requirements under Section 203 of the Water Resources Development Act (WRDA) of 1986, which authorizes non-Federal interests to undertake feasibility studies of proposed water resources development projects for submission to the Secretary of the Army?

Yes, USACE planning model quality guidance applies. Appendix B, Section j(2) of Engineer Regulation 1165-2-209, Studies of Water Resources Development Projects by non-Federal Interests addresses planning model quality assurance in studies undertaken by non-Federal interests.

Is it more difficult or time consuming to approve models developed by state agencies vs. models developed by USACE?

Models developed by state agencies are not necessarily harder to approve than models developed by USACE, but the effort and time required depends on how robust and well-documented the model is when it gets to USACE. Some models with detailed documentation that have already been peer reviewed move fairly quickly through the process, while others that are still in draft form and that lack an active point of contact at the submitting agency are much more difficult to review and approve.

Additionally, some models developed by others have parameters that are not USACE policy compliant. For example, some mitigation models developed by other federal agencies include a discount rate and risk factor. USACE does not discount habitat units per agency policy, and risk is accounted for in our monitoring and adaptive management requirements.

Do Districts typically collaborate with their resource agency partners (i.e., U.S. Fish and Wildlife Service, National Marine Fisheries Service) when developing their ecological planning models?

As best practices continue to be shared widely, the ECO-PCX is seeing increased coordination between Districts and their resource agency partners on model development and certification. The resource agencies are typically enthusiastic about getting involved in the model development process and sharing their expertise. They bring helpful field experience and peer review skills to the table that can improve model quality and make the certification process easier.

How long does it take for a model to be certified?

It depends on the complexity of the model. From the time you have complete model documentation in accordance with EC 1105-2-412, a typical timeline for model review and approval is 3-6 months.  This is estimating the time required to scope the review, identify appropriate reviewers, and review process, review time, USACE responses, and the time required for approval for use by the ECO-PCX Technical Director.  Areas where the timelines are typically held up include preparation of complete model documentation, failure to seriously address review comments, funding lapses for PDT and/or model proponent.

What happens if I don’t get the model I use certified?

HQ and the ATRT will notify the PDT that you have not complied with the EC’s and you will be directed to stop and conduct model review before you proceed.

What happens if my model review is conducted and the model is not certified?

If the review is conducted and significant issues arise that you cannot resolve through model modifications, you will be asked to assess the significance of the comments on the planning decision and how they effect your selection, and the vertical team will work with the PDT to resolve the issue.

How much does it cost to certify a model?

The costs vary based on the complexity of the model.  Costs for model review have been anywhere from $10 to $65k depending on review scope and review method.

What is the difference between approval for single-one time use and model certification?

The review process is basically the same.  The principal difference is the degree to which any significant comments have been resolved and the appropriateness for the model to be used on multiple applications.

We developed a Habitat Suitability Index model using HEP.  Does it need to be certified? 

Yes.  Although HEP is an accepted method, individual HSI models must go through the review process. 

Why do we need to review the quality of a model that has been published in a peer reviewed journal?

Models published in journal articles do not address policy, planning and forecasting, and applications.  They usually only focus on the technical aspects of a model.  They also do not review the use of the model in comparison of alternatives.  While journal publications contribute to the weight of evidence in support of the use of a model, the referee process does not address the many facets of the model applications related to Corps planning and policy.

When should I engage the PCX on model review requirements?

As soon as possible.  In your Review Plan you should describe and cite models you may potentially use in your study.  Prior to the AMM you should have a conceptual model of the system and a firm proposal of model(s) intended to be used for the study.  At this point you would develop a model review plan and coordinate with the ECO-PCX.  The review should be completed prior to using the model in decision-making.

EC 1165-2-412 expired – why should I be concerned with model review?

Guidance for assuring the quality of Planning models contained in EC 1105-2-412 remains in effect per PB 2013-01 until permanent Planning models guidance is issued as an Engineering Regulation. 

We used a group of outside technical experts to develop this model – who then is better qualified to review it?

We recommend that when you are developing your model, you reserve a few of the known experts to be available for review of your model as opposed to developing it.

This model is required by a local/state/Federal agency through statute/regulation/etc., why is model certification required for this model?

The group has a vested interest in the utility of the model.  Model review will ensure the model is unbiased and able to differentiate among alternatives consistent with Corps planning and policy.  If the local model does not meet Corps policy, it may be that you will need to use two models – one to meet the requirements of your locality and one that meets the requirements of quality for Corps planning and policy.


1999-09-30 ER1165-2-501 Civil Works Ecosystem Restoration Policy

2002 NAS Review Procedures for Water Resources Project 

2002-12-20 Memo DCW Planning Excellence Program

2003-08-25 Memo Establishing PCX Designations

2004-12-16 Memo about Final Information Quality Bulletin for Peer Review

2006-11-08 Memo - support_planning_centers_of_expertise

2007-11-08 WRDA 2007 -

2007-11-08 WRDA 2007 - IEPR Section 2034

2008-06-23 Memo PCX missions, roles and responsibilities

2008-08-__ ER ATR Review Guide

2011-01-19 Memo CAP Planning Process Improvements

2011-03-31 SEC 1105-2-412 Assuring Quality of Planning Models

2012-02-01 Model SOP

2012-03-__ GAO Peer Review Process for Civil Works Project Studies Can Be Improved

2012-12-15 EC 1165-2-214 Civil Works Review

2013-08-26 Delegated_Authority_IEPR_Over$45M

2013-11-__ 2013 Report to Congress on Peer Review 6yr_IPRR

2014-06-10 WRRDA 2014 - IEPR Law Section 1044

2016-03-04 PB 2016-02 Civil Works Review

2018-02-20 EC 1165-2-217 Review Policy for Civil Works

2019-06-11 IEPR SOP